Protective effects of total flavonoids in Caragana against hypoxia/reoxygenation-induced injury in human brain microvascular endothelial cells.

This study aimed to explore the protective effect of total flavonoids in Caragana against hypoxia/reoxygenation (H/R)-induced injury in human brain microvascular endothelial cells (BMECs). Human BMECs were selected and assigned into control, H/R, H/R+NMP, H/R+Low dose, H/R+Moderate dose, H/R+High dose groups. MTT and Transwell assays were used to detect cell viability and migration, respectively. Cell adhesion rate and tube formation were also detected. Real-time polymerase chain reaction (RT-PCR) and Western blotting were performed to test HIF-1α, VEGF and Notch1 mRNA and protein expressions. Compared with the H/R group, the cell viability rates in the H/R+NMP, H/R+Moderate dose and H/R+High dose groups were increased. The cell adhesion rates in the H/R+NMP, H/R+Moderate dose and H/R+High dose groups were significantly different from those in the H/R group. As compared to the H/R group, the cell migration abilities in the H/R+NMP, H/R+Moderate dose and H/R+High dose groups were enhanced. Compared with the H/R group, the number and length of tubes of BMECs in the H/R+NMP, H/R+High dose and H/R+Moderate dose groups were increased. HIF-1α, VEGF and Notch1 mRNA and protein expressions were higher in the H/R+Low dose, H/R+Moderate dose and H/R+High dose groups than in the H/R group. These findings revealed that total flavonoids in Caragana can protect BMECs from H/R-induced injury in a dose-dependent manner and it also may promote angiogenesis in BMECs by activating HIF- 1α-VEGF-Notch 1 signaling pathway.

Inhibited Expression of α4ß2 Nicotinic Acetylcholine Receptor in Blood Leukocytes of Chinese Patients with Vascular Dementia and in Blood Leukocytes as Well as the Hippocampus of Brain from Ischemic Rats.

Our present aim was to investigate whether changes in the expression of α4ß2 nicotinic acetylcholine receptor (nAChR) in patients with vascular dementia (VaD) and ischemic rats are related to cognitive scores. Blood leukocytes for 59 Chinese patients with VaD (diagnosed on the basis of clinical guidelines) and 31 cases as age-matched controls were examined, and the animal model established employing Pulsinelli's four-vessel occlusion. The levels of α4 and ß2 subunit mRNA in leukocytes and the hippocampus were analyzed by real-time PCR, and the protein level in the hippocampus by Western blotting. The mini-mental state examination was utilized to characterize the intellectual capacity of the patients with reference to the DSM IV diagnosis and Hachinski Ischemic Scale score, and the Morris Water Maze test to assess the ability of learning and memory of the rats. In patients, the level of α4 mRNA, but not ß2, in blood leukocytes was clearly lowered, which was significantly correlated to their clinical cognitive test scores. Smoking exerted no impact on the level of α4 mRNA in the present study. In the blood leukocytes and the hippocampus of the brains of the ischemic rats, the levels of both α4 and ß2 mRNA were lowered, and the proteins of these subunits in the hippocampus were decreased. The changes of α4 and ß2 mRNA in blood leukocytes, and their protein levels in the hippocampus were significantly correlated with impaired learning and memory. These findings indicate that alterations in expression of the α4ß2 subtype of nAChR may be involved in the molecular mechanism(s) underlying the cognitive deficit associated with VaD.

Correlations between cholinesterase activity and cognitive scores in post-ischemic rats and patients with vascular dementia.

The biochemical changes such as the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were investigated in rats with global cerebral ischemia and in vascular dementia (VaD) subjects in this study. The AChE activity showed a significant decrease in plasma and a significant increase in the hippocampus but not in the cerebral cortices in the post-ischemic rats as compared to the controls. The learning abilities and spatial memory were impaired in the post-ischemic rats as compared to controls. Furthermore, the AChE activity in plasma was significantly reduced in VaD subjects as compared to normal control subjects. The BuChE activity did not show any change in both post-ischemic rats and VaD patients. Interestingly, the decreased AChE activity in plasma from the post-ischemic rats and the VaD subjects showed a significant correlation with the declined learning and memory ability, and the Mini-Mental State Examination score, respectively. These data suggest that the AChE activity is involved in the cognitive recovery after ischemia, and the plasma level of AChE might be a reliable supplementary peripheral biomarker to evaluate the cognitive recovery degree of VaD patients.

Cholinesterase activity and mRNA level of nicotinic acetylcholine receptors (alpha4 and beta2 Subunits) in blood of elderly Chinese diagnosed as Alzheimer's disease.

The aim of the study is to investigate the cholinergic deficit in Alzheimer's disease (AD) and identify candidate blood biomarkers for the diagnosis of the disease. Twenty-nine elderly Chinese diagnosed with AD and 33 age-matched controls were selected. The activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in plasma were detected by a spectrophotometric method, and the mRNA levels of alpha4 and beta2 nicotinic acetylcholine receptor (nAChR) subunits in blood leukocytes were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that AChE activity in plasma was significantly lower in the AD group than in normal controls, while BuChE activity did not show any differences between AD and controls; mRNA levels of both alpha4 and beta2 nAChR subunits in blood leukocytes were significantly lower in the AD group than in controls. The AChE activity and the mRNA levels of alpha4 and beta2 nAChR subunits in the AD patients were also significantly correlated with cognitive test scores. No differences of AChE in plasma or alpha4 and beta2 nAChR subunits in blood leukocytes were detected between smoking and non-smoking subjects. The results indicated that the decreases in the activity of AChE and in the mRNA levels of nAChR alpha4 and beta2 subunits from the peripheral blood of patients with AD might serve as supplementary indicators for the clinical diagnosis of AD.